Thread: pgsql-server/ oc/src/sgml/datatype.sgml rc/bac ...

CVSROOT:    /cvsroot
Module name:    pgsql-server
Changes by:    momjian@svr1.postgresql.org    03/12/20 11:32:55

Modified files:
    doc/src/sgml   : datatype.sgml
    src/backend/commands: variable.c
    src/backend/utils/adt: datetime.c
    src/include    : miscadmin.h
    src/interfaces/ecpg/pgtypeslib: dt.h dt_common.c interval.c

Log message:
    In my mind there were two categories of open issues
    a) ones that are 100% backward (such as the comment about
    outputting this format)
    and
    b) ones that aren't (such as deprecating the current
    postgresql shorthand of
    '1Y1M'::interval = 1 year 1 minute
    in favor of the ISO-8601
    'P1Y1M'::interval = 1 year 1 month.

    Attached is a patch that addressed all the discussed issues that
    did not break backward compatability, including the ability to
    output ISO-8601 compliant intervals by setting datestyle to
    iso8601basic.

    Interval values can now be written as  ISO 8601 time intervals, using
    the "Format with time-unit designators". This format always starts with
    the character 'P', followed  by a string of values followed
    by single character time-unit designators. A 'T' separates the date and
    time parts of the interval.

    Ron Mayer

momjian@svr1.postgresql.org (Bruce Momjian) writes:
>     Attached is a patch that addressed all the discussed issues that
>     did not break backward compatability,

Was this patch actually agreed to?  I hadn't gotten around to looking
at it because I thought Peter was still objecting to the whole idea.

>       including the ability to
>     output ISO-8601 compliant intervals by setting datestyle to
>     iso8601basic.

This is a horrid, horrid idea.  Datestyle is already a complete mess
because it is being used to control several things; it should have been
two or possibly three GUC variables not one.  Sticking in yet another
behavior is just not acceptable IMHO, especially when it's defined as
non-orthogonally as that.

Please revert that part of the patch and instead invent a new GUC
variable that's specifically for interval formatting.

BTW, I can tell without looking that the patch is deficient in
documentation; if it has effects on GUC variables, why is there no
mod in runtime.sgml?

            regards, tom lane